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This retracts the article "" in volume 2013 on page 120231, which was published in final edited form.

This article has been retracted as it is essentially identical in title and technical content with the published article “Idempotent Elements of the Endomorphism Semiring of a Finite Chain,” by Ivan Trendafilov and Dimitrinka Vladeva, published in Comptes Rendus de L'Académie Bulgare des Sciences 66 (2013), no. 5, 621–628 (see [1]).